It has been shown that food allergy does not always manifest within the respiratory tract in such as obvious way as: dyspnea, cough or wheezing. The aim of the study was to evaluate the influence of food allergens on bronchial reactivity in children with asthma challenged with food.
A total of 304 patients (age range 5.5 to 18 years, mean 9.5 +/- 4.69 years) with atopic asthma were evaluated for food allergy by means of questionnaire, skin prick testing with food allergens, specific IgE tests (Unicap 100) and double-blind placebo-controlled food challenge (DBPCFC). Bronchial hyperreactivity was measured by methacholine inhalation challenges performed before and after DBPCFC in 70 asthmatic patients suspected of food allergy.
IgE-related food allergy was confirmed by DBPCFC in 24 asthmatic children. The mean FEV1 before and after food challenges in the group with IgE-related food allergy, as well as in the group without IgE-related food allergy, was not significantly different (p > 0.05). The mean PC20 in IgE-related food allergy group was 1.41 +/- 1.12 mg/ml and 0.86 +/- 0.71 mg/ml before and after food challenge respectively which was significantly different (p < 0.05). In the group without IgE-related food allergy the mean PC20 was 1.93 +/- 1.68 and 2.02 +/- 1.75 before and after challenge respectively (p > 0.05).
IgE-related food allergy was present in 9.8% children with asthma. Prevalence of respiratory manifestations induced by foods in children with asthma is 4.1%. Food challenges in these children increased bronchial reactivity, without exacerbation. Evaluation of food allergy in patients with asthma is indicated.